There is provided in a first form, a system including a detector and a reflector disposed about and proximal to the detector, at least of portion of the reflector being disposed in front of the detector. The reflector is configured to reflect at least a portion of the radiation directed to the system at an angle greater than a first predetermined value onto the detector, and the system is configured so that at least a portion of the radiation directed to the system at an angle less than the first predetermined value directly impinges on the detector.